1. Field of the Invention
The present invention relates to an electrostatic capacitive touch screen panel.
2. Discussion of the Related Art
In recent years, display devices, such as a liquid crystal display, an electroluminescent display, and a plasma display panel, having a quick response speed, low power consumption, and an excellent color reproduction rate, have been in the spotlight. These display devices have been used for various electronic products such as a television, a monitor for a computer, a laptop computer, a mobile phone, a display unit of a refrigerator, a personal digital assistant, and an automated teller machine. In general, these display devices interface with various input devices such as a keyboard, a mouse, and a digitizer. However, such input devices as a keyboard, a mouse, etc require the user to learn to use them and take up space, thus making it difficult to improve the completeness of the products. Therefore, the demand for input devices that are convenient and easy to use and reduce erroneous operations is growing more and more. In response to this demand, a touch screen panel for enabling a user to input information by directly touching the screen with their hand or a pen was suggested.
The touch screen panel has a simple configuration and has fewer malfunctions. Also, the user can perform an input action without using a separate input device and quickly and easily manipulate the touch screen panel through content displayed on the screen. Accordingly, the touch screen panel is being applied to various display devices.
Hereinafter, a related art electrostatic capacitive touch screen panel will be described with reference to FIGS. 1 and 2. FIG. 1 is a plan view showing a related art electrostatic capacitive touch screen panel. FIG. 2 is a plan view showing a dead zone on the related art electrostatic capacitive touch screen panel where touch recognition is impossible.
With reference to FIG. 1, the related art electrostatic capacitive touch screen panel comprises a panel portion PN with touch electrodes, routing wires, and grounding electrodes formed in a single layer, i.e., the same layer, and a flexible printed circuit board FPCB connected to one side of the panel portion PN and having wires for sending and receiving signals to and from the routing wires.
The touch electrodes of the panel portion PN are formed on a substrate SUB. The panel portion PN comprises a plurality of first touch electrodes Tx11, Tx12, Tx21, Tx22, Tx31, and Tx32 divided in a first direction (e.g., x-axis direction, i.e., row direction) and a second direction (e.g., y-axis direction, i.e., column direction) crossing the first direction, a plurality of 2-1 and 2-2 touch electrodes Rx1 and Rx2 disposed on one side of the 1-1 and 1-2 touch electrodes Tx11, Tx21 and Tx31; and Tx12, Tx22 and Tx32 along the column direction, and first and second grounding electrodes G1 and G2 disposed on the other side of the 1-1 and 1-2 touch electrodes Tx11, Tx21 and Tx31; and Tx12, Tx22 and Tx32 along the column direction.
The routing wires of the panel portion PN comprise 1-1 main routing wires TW11a, TW21a, and TW31a which are disposed between the 1-1 touch electrodes Tx11, Tx21, and Tx31 of the first column and the first grounding electrode G1 and respectively connected to the 1-1 touch electrodes Tx11, Tx21, and Tx31 of the first column and extend in the second direction, and 1-2 main routing wires TW12a, TW22a, and TW32a which are disposed between the 1-2 touch electrodes Tx12, Tx22, and Tx32 of the second row and the second grounding electrode G2 and respectively connected to the 1-2 touch electrodes Tx12, Tx22, and Tx32 of the second column and extend in the second direction.
The routing wires of the panel portion PN further comprise a 2-1 main routing wire RW1a connected to the 2-1 touch electrode Rx1 of the first column and extending in the second direction, and a 2-2 main routing wire RW2a connected to the 2-2 touch electrode Rx2 of the second column and extending in the second direction.
The routing wires of the panel portion PN further comprise a first main grounding wire GW1a connected to the first grounding electrode G1 and extending in the second direction, and a second main grounding wire GW2a connected to the second grounding electrode G2 and extending in the second direction.
The flexible printed circuit board FPCB comprises 1-1 sub routing wires TW11b, TW21b, and TW31b attached to one side of the panel portion PN and respectively connected to the 1-1 main routing wires TW11a, TW21a, and TW31a, 1-2 sub routing wires TW12b, TW22b, and TW32b respectively connected to the 1-2 main routing wires TW12a, TW22a, and TW32a, 1-1 to 1-3 connecting wires TW1c, TW2c, and TW3c connecting the 1-1 sub routing wires TW11b, TW21b, and TW31b to the 1-2 sub routing wires TW12b, TW22b, and TW32b, and 1-1 to 1-3 signal wires TW1, TW2, and TW3 respectively connected to the 1-1 to 1-3 connecting wires TW1c, TW2c, and TW3c and extending to the edge of the flexible printed circuit board FPCB.
The flexible printed circuit board FPCB further comprises a 2-1 signal wire RW1 connected to the 2-1 main routing wire RW1a and extending to the edge of the flexible printed circuit board FPCB, and a 2-2 signal wire RW2 connected to the 2-2 main routing wire RW2a and extending to the edge of the flexible printed circuit board FPCB.
The flexible printed circuit board FPCB further comprises a first sub grounding wire GW1b connected to the first main grounding wire GW1a, a second sub grounding wire GW2b connected to the second main grounding wire GW2a and extending to the edge of the flexible printed circuit board FPCB.
The related art electrostatic capacitive touch screen panel with the above-described configuration detects a touch position by supplying touch driving signals to the 1 touch electrodes Tx11 and Tx12 of the first row, the 1 touch electrodes Tx21 and Tx22 of the second row, and the 1 touch electrodes Tx31 and Tx32 of the third row, sensing the 2-1 and 2-2 touch electrodes Rx1 and Rx2, and calculating a change before and after a touch in the mutual capacitance occurring between the 1 touch electrodes Tx11, Tx21, Tx31 and 2-1 touch electrodes Rx1, and the 1 touch electrodes Tx12, Tx22, Tx32 and the 2-2 touch electrode Rx2.
The related art electrostatic capacitive touch screen panel has the advantage of ease of manufacture because it has a single layer structure; however, it requires first and second grounding electrodes G1 and g2 for separating the 1-1 and 1-2 main routing wires TW11a, TW12a and TW31a; and TW12a, TW22a and TW32a because the first touch electrodes and the second touch electrodes must be formed in the same layer, as shown in FIG. 2.
By the way, no mutual capacitance occurs between the first touch electrodes Tx11, Tx21, and Tx31 and the second touch electrode Rx2, which lie on either side of the first grounding electrode G1, due to the first and second grounding electrodes G1 and G2. As such, when the user touches the space between the first touch electrodes Tx11, Tx21, and Tx31 and the second touch electrode Rx2, a dead zone occurs where a touch position cannot be precisely recognized.